Vehicle multi-processor control system and method with processing load optimization

ABSTRACT

An automatic control system comprises a plurality of control processors which are connected by such transmission devices as LAN, BUS and so on. Control processing load to be executed by each of the control processors are detected and each control processor executes necessary and minimum control tasks corresponding to running state information on an automobile and carries on another control tasks in the remaining time based on the detected load of each control processor so as to smooth loads of the control processors.

This application is a continuation of application Ser. No. 08/249,619,filed on May 26, 1994, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a control system installed in anautomobile, particularly to a method and a system for controlling anautomobile comprising a plurality of control units using computers toexecute various kinds of controls.

2. Description of the Related Art

As a conventional method for controlling each part of an automobile byuse of plural control units, one described in A Japan Patent ApplicationLaid-Open 243426/1991 is known.

In this conventional method, plural computers monitor the presence oftroubles in each other and execute cooperative operations by changingcontrol tasks in accordance with the presence of troubles in anothercomputer.

Although the control tasks executed in a computer itself can be changedin accordance with the presence of troubles in other computers by theabove-mentioned conventional method, a computer does not execute tasksto be executed in another computer, taking the place of another computerin accordance with load states of another computer.

For example, control tasks are executed by such exclusive processors asan engine control exclusive processor, an automatic transmission (AT)control exclusive processor and so on. Then, while some exclusiveprocessor has no control task to execute, the processor has wastefultime not to be utilized. For instance, an automatic braking system (ABS)exclusive processor must execute control tasks for ABS at the brakingtime. On the other hand, control tasks for the ABS would be wastefullydone at the non-braking time.

SUMMARY OF THE INVENTION

1. Objects of the Invention

The present invention has been achieved in consideration of theabove-described problems, and is aimed at providing a method and asystem to adjust the processing amount of each control unit by adding orremoving some tasks to or from control units in accordance with theprocessing amount (control load) of each control unit whose control loadchanges corresponding to running states of an automobile.

2. Methods Solving the Problems

The fundamental features of the present invention are to provide acontrol method of an automobile wherein at least one control unitexecutes at least one control task program of another control unithaving higher control load in controlling each part of an automobile byconnecting a plurality of control units using computers with atransmission line, and to provide a control system of an automobilewherein a plurality of control units using computers for controllingeach part of an automobile are connected with a transmission line and atleast one of the control units has at least one electrically rewritablememory for storing at least one control task program of another controlunit having higher control load.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a constitution block diagram of an embodiment of an automobilecontrol system.

FIG. 2 is a constitution block diagram of another embodiment of anautomobile control system.

FIG. 3 shows a concept of a cooperative control of an automobile.

FIG. 4 is a flow chart showing an embodiment of executing OBD processingat the low load time of an ABS control processor.

FIG. 5 is a flow chart showing an embodiment of a cooperative control byan ABS control processor.

FIG. 6 shows an embodiment of a hardware constitution of a cooperativecontrol apparatus.

FIGS. 7A-7B are flow charts showing an embodiment of a cooperativeautomobile control method by adopting interruption processing onbraking.

FIGS. 8A-8B are flow charts showing another embodiment of a cooperativeautomobile control method by adopting interruption processing onbraking.

FIGS. 9A-9E are flows chart showing an embodiment of a cooperativeautomobile control method by adopting interruption processing andcontent change of a vector base register on braking.

FIG. 10A-10E are flow charts showing another embodiment of a cooperativeautomobile control method by adopting interruption processing andcontent change of a vector base register on braking.

FIG. 11 shows a block diagram of an embodiment in which a plurality ofprocessors for cooperatively controlling an automobile are connected bytransmission means.

FIGS. 12(a) and 12(b) are flow charts showing an embodiment of anautomobile control cooperatively conducted by an ABS and an ASCD controlprogram.

FIGS. 13(a) and 13(b) are flow charts showing another embodiment of anautomobile control cooperatively conducted by an ABS and an ASCD controlprogram.

FIGS. 14A-14B are flow charts showing an embodiment of executing anotherprogram based on load detection in an AT control processor.

FIGS. 15A-15B are flow charts showing another embodiment ofcooperatively executing another program based on load detection in an ATcontrol processor.

FIG. 16 shows a block diagram of an embodiment in which an I/O controlprocessor detects loads of other processors for cooperativelycontrolling an automobile.

FIGS. 17(a) and 17(b) are flow charts showing an embodiment of detectingloads of other control processors by an I/O control processor incooperatively controlling an automobile.

FIGS. 18(a) and 18(b) are flow charts showing another embodiment ofdetecting loads of other control processors by an I/O control processorin cooperatively controlling an automobile.

FIG. 19 shows a block diagram of an embodiment in which integral typeprocessors are used for cooperatively controlling an automobile.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, details of the present invention are explained based onembodiments referring to drawings.

FIG. 1 is a constitution block diagram of an embodiment of an automobilecontrol system.

The load states in control tasks of each of control units A 101 and B102 are detected from the present running states and the load states ofeach of control units A 101 and B 102 by a load detecting means A 100, aprogram determined based on the load states from programs stored in eachof memorizing means A 103 and B 104 is executed, and each of actuators A107 and B 108 are controlled by each of control means A 105 and B 106.In this case, the load states of a control unit B 102 are detected bythe load detecting means A 100 and the detected load states aretransmitted to the control means B 106 and the memorizing means B 104via a transmission line 109 such as a LAN or a BUS. The above-mentionedprocessing can be done by providing a load detecting means B 110.

The control is carried out to the actuator B 108 via the transmissionline 109 such as LAN or BUS in case a program in the memorizing means A103 controls the actuator B 108. The control is similarly carried out tothe actuator A 107 via the transmission line 109 such as LAN or BUS incase a program in the memorizing means B 104 controls the actuator A107.

In the case of an ABS control and an ABS self-diagnosing program storedin the memorizing means A 103, and an engine control program and anOn-Board Diagnosis (OBD) program in the memorizing means B 104, thecontrol task load states of the control units A 101 and B 102 aredetected by the load detecting means A 100 and programs adequate to theload states are executed. For example, whether a brake is put on or notis detected by the load detecting means A 100, and if it is put on, thenthe ABS control program is executed, and if it is not, then the ABSself-diagnosing program and the OBD program are executed, in the controlunit A 101. In the control unit B 102, if it is put on, then the enginecontrol program and the OBD program are executed, and if it is not, thenonly the engine control program is executed.

FIG. 2 is a constitution block diagram of another embodiment of anautomobile control system. The outputs of sensors 1 for detecting suchstate variables indicating the running states of an automobile such as arunning speed, a throttle opening, an engine revolution number, a gearposition and so on are input into a load detecting means 2, the loadstates in control tasks of control means A 3 and B 4 needed to be donecorresponding to the detected running states are judged by the loaddetecting means 2 and the judged load states are sent to the controlmeans A 3 and B 4. The control means A 3 and B 4 change control taskscorresponding to the load states and control the actuators A 5 and B 6to an injection system, an ignition system, a shift solenoid, alock-up-solenoid, a brake, etc.. And, if the contents of a control taskto be executed by the control means A 3 are not stored in the memorizingmeans A 7 but in the memorizing means B 7, the contents of the controltask stored in the memorizing means B 8 is read out and written into thememorizing means A 7 via the transmission line 9 and executed by thecontrol means A 3. Now, it is assumed that the ABS control program isstored in the memorizing means A 7 which also comprises suchelectrically rewritable memories as an electrically erasable andprogrammable read only (E² PPROM) or a flash memory, and the enginecontrol and the OBD program are stored in the memorizing means B 8. Inthis case, an output signal of a brake switch (SW) is taken into theload detecting means 2 and whether the brake SW is ON or OFF isdetected. If the brake SW is on, then the ABS control is executed by thecontrol means A 3 and the engine control by the control means B 4. Andif the brake SW is OFF, then the OBD program stored in the memorizingmeans B 8 is read out and written into the electrically rewritablememory via the transmission line 9, executed by the control means A 3,and the engine control is done by the control means B 4. It is possibleto efficiently carry out the controls since the OBD can be done when theABS control is not to be executed. Further, production cost can bereduced since an exclusive control means to the OBD is not necessary.

FIG. 3 shows a concept of a cooperative control of an automobile. At thestart or the stationary running state, the processing load needed to aprocessor for the ABS control is less in comparison with the maximumprocessing ability of the processor and the processor may executewasteful processing. On the other hand, the processor for the ABScontrol fully uses its processing ability on braking. Although aprocessor for an AT control fully uses its processing ability at thestart state, the processor carries out wasteful processes since theneeded processing load is a little. Since the OBD and the engine controlare always executed at the start and the stationary running state, itbecomes possible to efficiently use the processors for the ABS controland the AT control by executing the OBD processing at the low processingload time of the processors for the ABS and the AT control.

FIG. 4 is a flow chart showing an embodiment of executing OBD processingat the low load time of an ABS control processor. When a power turns on,initialization of a timer, a port, an A/D converter, RAM, a transmissionsystem, etc. is done at the step 2000, an output signal of a brake SW istaken in at the step 2010, and whether the brake SW is ON or OFF isjudged at the step 2020. And, if the brake SW is ON, then the ABScontrol is executed at the step 2030 and the process goes back to thestep 2010 of taking in the output signal of the brake SW. If the brakeSW is OFF, then the ABS self-diagnosis is executed at the step 2040, theOBD program stored in advance in the ABS control processor is executedat the step 2060 and the process goes back to the step 2010.

FIG. 5 is a flow chart showing an embodiment of cooperative control byan ABS control processor. When a power turns on, initialization of atimer, a port, an A/D converter, RAM, a transmission system, etc. isdone at the step 2001, an output signal of a brake SW is taken in at thestep 2011, and whether the brake SW is ON or OFF is judged at the step2021. And, if the brake SW is ON, then the ABS control is executed atthe step 2031 and the process goes back to the step 2011 of taking inthe output signal of the brake SW. If the brake SW is OFF, then the ABSself-diagnosis is executed at the step 2041. And, whether the OBDprogram was read out and written into the ABS control processor fromanother processor is judged at the step 2051. If the program is alreadyread out and written, then the OBD program is executed at the step 2061,and if it is not read out and written yet or another program is alreadywritten, then the OBD program stored in the engine control processor isread out and written at the step 2071. Then, the read out and writtenOBD program is executed at the step 2061 and the process goes back tothe step 2011. In this case, the ABS control processor and the enginecontrol processor are the same kind, and the address in the enginecontrol processor of the OBD program to be read out and written is thesame address in the ABS control processor of the read out OBD program.By such agreement in both addresses of the memories at which the programare stored, the program can be read out and written without anycorrection and executed at the processor to which the program is readout and written as it was. If the program is written into a differentaddress, the processor has a linking function for adjusting theaddresses in a branching process or the data addresses and reads out andwrites the program. And, if the program is written into a different kindof a processor, the program is read in the source program form of Clanguage and compiled by a C compiler at the processor into which theprogram is written. The ABS control program carries out theself-diagnosis for checking normal operation of a brake system andsensors of wheel revolution speeds, disconnection of sensor wiring, etc.However, there happens such wasteful processing that the same resultsare calculated by using the same data since the self-diagnosis onlyrequires shorter computing time than the data renewal interval. Then, itbecomes possible to efficiently use a processor by such a programexecuting another function as the OBD program in accordance with theload states of a processor. Now, if a electrically rewritable memoryhaving the restriction to rewriting times is used, it is needed tomemorize the number of the executed rewriting times.

FIG. 6 shows an embodiment of a hardware constitution of a cooperativecontrol apparatus. An ABS control unit 10 comprises a processor 11, aROM 12, a RAM 13, a ROM or an electrically rewritable memory 14, an I/Oport 15, an A/D converter 16, a timer 17 and a transmission signalcontrol circuit 18, and the ROM 12 includes a load detecting, atransmission and an ABS control program. If the memory 14 is a ROM,programs except the programs stored in the ROM 12 are stored in thememory 14 in advance, and if the memory is an electrically rewritablememory, programs stored in other control units connected to the ABScontrol unit are stored in the memory 14 via a transmission circuit 18.In this case, only the OBD program is stored in the memory 14, butanother program such as a program for an Auto-Speed-Control Device(ASCD) may be stored in the ROM 14 of the ABS control unit in advance oranother program such as a program for ASCD stored in the ROM of theengine control unit may be read out and written into the electricallyrewritable memory 14 of the ABS control unit. Further, the ROM 12, theRAM 13, the ROM or the electrically rewritable memory 14, the I/O port15, the A/D converter 16, the timer 17 and the transmission circuit 18can be provided outside the ABS control unit 10. The engine control unit20 comprises a processor 21, a ROM 22, a RAM 23, a I/O port 25, a A/Dconverter 26, a timer 27 and a transmission circuit 28 and the ROM 22includes a load detecting, a transmission, an engine control and an OBDprogram. Further, the engine control unit 10 as well as the ABS controlunit 20 may include an electrically rewritable memory, and such devicesas the ROM 22, the RAM 13, the electrically rewritable memory (not shownin the figure), the I/O port 25, the A/D converter 26, the timer 27 andthe transmission circuit 28 can be provided outside the engine controlunit 20. The I/O port, the A/D converter and the timer of each controlunit are connected to such sensors or actuators needed to control eachpart of an automobile such as wheel revolution speed sensors 34, a brake33, an opening sensor of a throttle 30, an engine revolution speedsensor 30, an air flow meter 30, a brake switch sensor 31, brakeactuators 32, an injection actuator 30, an ignition actuator 30 and soon.

FIGS. 7A-7B are flow charts showing an embodiment of an cooperativeautomobile control method by adopting interruption processing onbraking. When the power turns on, initialization of a timer, a port, anA/D converter, a RAM, a transmission system, etc. is done at the step3000, an ABS self-diagnosis for checking normal operation of a brakesystem and sensors of wheel revolution speeds, disconnection of sensorwiring, etc. is done at the step 3010, an OBD processing by the OBDprogram stored in advance is done at the step 3030 and the process goesback to the step 3010 of the ABS self-diagnosis. Usually the steps from3010 to 3030 are repeated. If the brake SW turns ON, the interruptionoccurs (3050) and the ABS processing for which a program is stored inadvance, for example, in an electrically rewritable memory is executedat the step 3060. The interruption receiving is continued for thepredetermined intervals after brake-SW-ON and the change frombrake-SW-ON to brake-SW-OFF since only one time braking is rarelyconducted but braking is usually conducted several times. Execution ofthe ABS program by adopting the interruption processing as mentionedabove can realize quick control without time delay.

FIGS. 8A-8B are flow charts showing another embodiment of an cooperativeautomobile control method by adopting interruption processing onbraking. In the processing (A) of FIG. 8, when a power turns on,initialization of a timer, a port, an A/D converter, a RAM, atransmission system, etc. is done at the step 3001, and an ABSself-diagnosis for checking normal operation of a brake system andsensors of wheel revolution speeds, disconnection of sensor wiring, etc.is done at the step 3011. And, whether an OBD program was read out andwritten into the processor from another processor is judged at the step3021. If the program is already read out and written, and an OBDprocessing is done at the step 3031 , and if it is not read out andwritten yet or another program is written, then the OBD program storedin another processor is read out and written at the step 3041. Then, theread out and written OBD program is executed at the step 3031 and theprocess goes back to the step 3011 of the ABS self-diagnosis. Usuallythe steps from 3011 to 3031 are repeated. On the other hand, in theprocessing (B) of FIG. 8, if the brake SW turns ON, the interruptionoccurs (3051) and an ABS processing is executed at the step 3061. Theinterruption receiving is continued for the predetermined intervalsafter brake-SW-ON and the change from brake-SW-ON to brake-SW-OFF sinceonly one time braking is rarely conducted but braking is usuallyconducted several times. Execution of the ABS program by adopting theinterruption processing as mentioned above can realize quick controlwithout time delay. Furthermore, it is possible to smooth loads ofprocessors used for automobile control by the cooperative control methodwherein a processor in the lower load states execute a program which isstored in another processor in the higher load states and read out andwritten into the processor in the lower load states as explained in theabove embodiment.

FIGS. 9A-9E are flow charts showing an embodiment of a cooperativeautomobile control method by adopting interruption processing andcontent change of a vector base register on braking. When a power turnson, initialization of a timer, a port, an A/D converter, a RAM, atransmission system, etc. is done at the step 4000, an ABSself-diagnosis for checking normal operation of a brake system andsensors of wheel revolution speeds, disconnection of sensor wiring, etc.is done at the step 4010. On the other hand, the interruption is broughtabout by a timer in every 10 ms and if the content of a vector baseregister is X (4020), then an OBD processing by an OBD program stored inadvance is executed at the step 4040. And, if the content of the vectorbase register is Y (4100), then an ABS processing is executed at thestep 4110. The content change of the vector base register is caused bythe interruption on braking (4060) and the interruption on brake offdelay (4080). If the brake SW is ON, then the interruption on brakingoccurs (4060) and the content of the vector base register is changed toY at the step 4070. And, if the brake SW is OFF, then the interruptionon brake off delay occurs (4080) and the content of the vector baseregister is changed to X at the step 4090. As explained above, differentprograms can be executed by changing the content of the vector baseregister in the same interruption processing.

FIGS. 10A-10E are flow charts showing another embodiment of acooperative automobile control method by adopting interruptionprocessing and content change of a vector base register on braking. Inthe process (A) of FIG. 10, when the power turns on, initialization of atimer, a port, an A/D converter, a RAM, a transmission system, etc. isdone at the step 4001, and an ABS self-diagnosis for checking normaloperation of a brake system and sensors of wheel revolution speeds,disconnection of sensor wiring, etc. is done at the step 4011. On theother hand, in the process (B) of FIG. 10, the interruption is broughtabout by a timer in every 10 ms and if the content of the vector baseregister is X (4021), then whether an OBD program was read out andwritten into the processor from another processor is judged at the step4031. If the program is already read out and written, then the OBDprocessing is done at the step 4041, and if it is not read out andwritten yet or another program is already written, then the OBD programstored in another processor is read out and written at the step 4051.Then, the read out and written OBD program is executed at the step 4041.Then, in the processing (E) of FIG. 10, if the content of the vectorbase register is Y (4101), an ABS processing is executed. The contentchange of the vector base register is done by the interruption (4061) onbraking shown by the processing (C) of FIG. 10 or by the interruption(4081) on brake off delay shown by the processing (D) of FIG. 10, and ifthe brake SW is on, then the interruption on braking occurs (4061) andthe content of the vector base register is changed to Y at the step4071. At a predetermined interval after the change from brake-SW-ON tobrake-SW-OFF, the interruption on brake off delay occurs at the step4081 and the content of the vector base register is changed to X at thestep 4091. As explained above, different programs can be executed bychanging the content of the vector base register in the sameinterruption processing. Further, it is possible to smooth loads ofprocessors used for automobile control by the cooperative control methodwherein a processor in the lower load states execute a program which isstored in another processor in the higher load states and read out andwritten into the processor in the lower load states as explained in theabove embodiment.

FIG. 11 shows a block diagram of an embodiment in which a plurality ofprocessors for cooperatively controlling an automobile are connected bytransmission means. Processors used to cooperative automobile controlfor such systems as an engine (ENG) 40, an automatic transmission (AT)41, an ABS 42, an ASCD 43, an air bag system (AirBS) 44, an OBD system45, a traction system (TCS) 46, an I/O control processor 47, an activesuspension (SUS), a navigation system (NAVI) 49, a light system (LIGHT)50, an air conditioner (A/C) 51, a power steering system (PWST) 52, anaudio/video system (AV) 53, a power window system (PWWD) 54, a wipersystem (WIPER) and so on are connected by transmission means such as LANor BUS. An electrically rewritable memory 14 is provided in the ABScontrol processor, and when the load of the ABS control processor islow, a program stored in another processor is read out and written intothe rewritable memory 14 and executed by the ABS control professor.Further, an electrically rewritable memory 14 may be provided in acontrol processor except the ABS control processor, and a program storedin another control processor except the processor having theelectrically rewritable memory may be read out and written into therewritable memory and executed. By the above-mentioned control system inwhich a plurality of control processors are connected by transmissionmeans, plural programs stored in plural processors can be read out andwritten into an electrically rewritable memory 14 in turn and executed.Further, if the memory is managed by the virtual memory method, programshaving the size beyond the capacity of the memory can be executed. Then,a processor can executes all programs stored in the processors connectedto each other by transmission means.

FIGS. 12(a) and 12(b) are flow charts showing an embodiment of anautomobile control cooperatively conducted by an ABS and an ASCD controlprogram. In the ABS control program shown by FIG. 12(a), when the powerturns on, initialization of a timer, a port, an A/D converter, a RAM, atransmission system, etc. is done at the step 5000, an output signal ofa brake SW is taken in at the step 5010, and whether the brake SW is ONor OFF is judged at the step 5020. And, if the brake SW is ON, then anABS control is executed at the step 5030 and the process goes back tothe step 5010 of taking in the output signal of the brake SW. If thebrake SW is OFF, an output signal of an ASCD cruising SW is taken in atthe step 5040, and whether an ASCD control is ON or OFF is judged at thestep 5050. And, if the ASCD control is ON, then the ASCD diagnosisprogram stored in advance is executed by the ABS control processor atthe step 5070, and if the ASCD control is in OFF, then the ABSself-diagnosis and an OBD program stored in advance are executed at thesteps 5080 and 5100 and the process goes back to the step 5010 of takingin an output signal of a brake SW. Those processes are repeated. In theASCD control program shown by FIG. 12(b), when a power turns on,initialization of a timer, a port, an A/D converter, a RAM, atransmission system, etc. is done at the step 6000, the output signal ofthe ASCD cruising SW is taken in at the step 6010, and whether the ASCDcontrol is ON or OFF is judged at the step 6020. And, if the ASCDcontrol is ON, then the ASCD control is executed at the step 6030 andthe process goes back to the step 6010 of taking in the output signal ofthe ASCD cruising SW. If the ASCD control is OFF, the output signal ofthe brake SW is taken in at the step 6040, and whether the brake SW isON or OFF is judged at the step 6050. And, if the brake SW is ON, thenthe ABS diagnosis stored in advance is executed by the ASCD controlprocessor at the step 6070, and if the brake SW is OFF, then the ASCDself-diagnosis and the OBD stored in advance are executed at the steps6080 and 6100 and the process goes back to the step 6010 of taking inthe output signal of the ASCD cruising SW. Those processes are repeated.By the embodiment, the processors are efficiently used and the safety onrunning of an automobile is also improved since the ABS diagnosis isexecuted by the ASCD control processor whose load is a little when theload of the ABS control processor is much and vice versa, and furtherthe both processor execute the OBD program in the remaining time. Then,control processing speed is improved as a whole by supporting taskexecutions to be done in other processors. Although the cooperativeautomobile control by the ABS and the ASCD control is described in thisembodiment, the present invention is not restricted to the embodiment.In the cooperative automobile control by the present invention, sinceall processors for controlling an automobile are connected bytransmission means and the loads of the processors are smoothed inaccordance with task amounts of each processor which changecorresponding to running states of an automobile, the processors areefficiently used, and control processing speed and also the runningsafety of an automobile are improved.

FIGS. 13(a) and 13(b) are flow charts showing another embodiment of anautomobile control cooperatively conducted by an ABS and an ASCD controlprogram. In the ABS control program shown by FIG. 13(a), when the powerturns on, initialization of a timer, a port, an A/D converter, a RAM, atransmission system, etc. is done at the step 5001, an output signal ofa brake SW is taken in at the step 5011, and whether the brake SW is ONor OFF is judged at the step 5021. And, if the brake SW is ON, then anABS control is executed at the step 5031 and the process goes back tothe step 5011 of taking in the output signal of the brake SW. If thebrake SW is OFF, an output signal of an ASCD cruising SW is taken in atthe step 5041, and whether an ASCD control is ON or OFF is judged at thestep 5051. And, if the ASCD control is ON, then an ASCD diagnosis isread out and written into an electrically rewritable memory of an ABScontrol processor at the step 5061 and executed at the step 5071, and ifthe ASCD control is in OFF, then an ABS self-diagnosis is executed. And,whether an OBD program was read out and written into the ABS controlprocessor from another processor is judged at the step 5091. If theprogram is already read out and written, then the OBD program isexecuted at the step 5101, and if it is not read out and written yet oranother program is written, then the OBD program stored in an enginecontrol processor is read out and written at the step 5111. Then, theread out and written OBD program is executed at the step 5101 and theprocess goes back to the step 5011. On the other hand, in the ASCDcontrol program shown by FIG. 13(b), when a power turns on,initialization of a timer, a port, an A/D converter, a RAM, atransmission system, etc. is done at the step 6001, an output signal ofan ASCD cruising SW is taken in at the step 6011, and whether the ASCDcontrol is ON or OFF is judged at the step 6021. And, if the ASCDcontrol is ON, then the ASCD control is executed at the step 6031 andthe process goes back to the step 6011 of taking in the output signal ofthe ASCD cruising SW. If the ASCD control is OFF, the output signal ofthe brake SW is taken in at the step 6041, and whether the brake SW isON or OFF is judged at the step 6051. And, if the brake SW is ON, thenthe ABS diagnosis is read out and written into an electricallyrewritable memory of the ASCD control processor at the step 6061 andexecuted at the step 6071, and if the brake SW is OFF, then an ASCDself-diagnosis is executed. And, whether the OBD program was read outand written into the ASCD control processor is judged at the step 6091.If the program is already read out and written, then the OBD program isexecuted at the step 6101, and if it is not read out and written yet oranother program is already written, then the OBD program stored in theengine control processor is read out and written at the step 6111. Then,the read out and written OBD program is executed at the step 6101 andthe process goes back to the step 6011. By the embodiment, theprocessors are efficiently used and the safety on running of anautomobile is also improved since the ABS diagnosis is executed by theASCD control processor whose load is a little when the load of the ABScontrol processor is much and vice versa, and further the both processorexecute the OBD program in the remaining time. In the execution of theOBD program, if the OBD program is not read out and not written intoeach of the ABS and the ASCD control processor yet, each program readsout and writes the OBD program into an electrically rewritable memoryprovided in each processor. Then, control processing speed is improvedby supporting task executions to be done in other processors. Althoughthe cooperative automobile control the ABS and the ASCD control isdescribed in this embodiment, the present invention is not restricted tothe embodiment. In the cooperative automobile control by the presentinvention, since all processors for controlling an automobile areconnected by transmission means and the loads of the processors aresmoothed in accordance with task amounts of each processor which changecorresponding to running states of an automobile, the processors areefficiently used, and control processing speed and also the runningsafety of an automobile are improved.

FIG. 14 is a flow chart showing an embodiment of executing anotherprogram based on load detecting in an AT control processor. In an ATcontrol program, when the power turns on, initialization of a timer, aport, an A/D converter, a RAM, a transmission system, etc. is done atthe step 7000, a program process-able within remaining time is decidedat the step 7010, a target program is executed at the step 7030 and theprocess goes back to the step 7010 of deciding a program process-ablewithin remaining time. The remaining time is the time of subtracting theAT control processing time needed to run an automobile from the timeinterval for invoking the AT control program, in which controls exceptthe AT control can be executed. The AT control program invoked by 10 msinterruption judges the running states from the wheel revolution speed,the number of engine revolution, the number of turbine revolution, theopening of throttle, the gear position, the range SW position, thechange gear mode SW position, etc. at the step 7050, executes the ATcontrol in accordance with the running states at the step 7060, andcalculates the remaining time at the step 7070. The calculation of theremaining time is done by using the value of a timer counter forinvoking the 10 ms interruption. Other timer counters can be also used.The embodiment is effectual for such a control whose processing timechanges corresponding to the running states as the AT control.

FIGS. 15A-15B are flow charts showing another embodiment ofcooperatively executing another program execution based on loaddetecting in an AT control processor. In the process (A) of FIG. 15,when the power turns on, initialization of a timer, a port, an A/Dconverter, a RAM, a transmission system, etc. is done at the step 7001,a program process-able within remaining time is decided at the step7011. And, whether the decided target program was read out and writteninto the AT control processor from another processor is judged at thestep 7021. If the program is already read out and written, then thetarget program is executed at the step 7031, and if it is not read outand written yet or another program is already written, then the targetprogram stored in another processor is read out and written at the step7041. Then, the read out and written target program is executed at thestep 7031 and the process goes back to the step 7011. In the process (B)of FIG. 15, the AT control program invoked by 10 ms interruption judgesthe running states from the wheel revolution speeds, the number ofengine revolution, the numbers of turbine revolution numbers, theopening of throttle, the gear position, the range SW position, thechange gear mode SW position, etc. at the step 7051, executes the ATcontrol in accordance with the running states at the step 7061, andcalculates the remaining time at the step 7071. The calculation of theremaining time is done by using the value of a timer counter forinvoking the 10 ms interruption. Another timer counter can be also used.The embodiment is effectual for such a control whose processing timechanges corresponding to the running states as the AT control. Further,it becomes possible to smooth loads of processors by executing a targetprogram stored in another processor in accordance with the load statesof the AT control processor.

FIG. 16 shows a block diagram of an embodiment in which an I/O controlprocessor detects loads of other processors for cooperativelycontrolling an automobile. Processors used to cooperative automobilecontrol for such systems as an engine (ENG) 41, an automatictransmission (AT) 41, an ABS 42, an ASCD 43, an air bag system (AirBS)44, an OBD system 45, a traction system (TCS) 46, an I/O controlprocessor 47, an active suspension (SUS), a navigation system (NAVI) 49,a light system (LIGHT) 50, an air conditioner (A/C) 51, a power steeringsystem (PWST) 52, an audio/video system (AV) 53, a power window system(PWWD) 54, a wiper system (WIPER) and so on are connected bytransmission means such as LAN or BUS. In the I/O processor 47, afunction 56 for detecting loads of other processors and delivering theinformation on load of each processor to other processors is provided.By the function 56 of the I/O processor 47, the processing speed of eachprocessor is increased since each processor except the I/O processor hasnot to detect loads of processors. The load detection can be also doneby a processor except the I/O processor or plural processors. And,providing an exclusive processor for the load detection is alsoeffective.

FIGS. 17(a) and (b) are flow charts showing another embodiment ofdetecting loads of other control processors by an I/O control processorin cooperatively controlling an automobile. In the I/O control programshown by FIG. 17(a), when a power turns on, initialization of a timer, aport, an A/D converter, an RAM, a transmission system, etc. is done atthe step 8000, an output signal of a brake SW is taken in at the step8010, and whether the brake SW is ON or OFF is judged at the step 8020.And, if the brake SW is ON, then the I/O control program sends theinformation of the brake-SW-ON at the step 8030 to the ABS controlprocessor. If the brake SW is OFF, then the I/O control program sendsthe information of the brake-SW-OFF at the step 8040 to the ABS controlprocessor and the process goes back to the step 8010. In the ABS controlprogram shown by FIG. 17(b), when a power turns on, initialization of atimer, a port, an A/D converter, a RAM, a transmission system, etc. isdone at the step 9000, the brake SW state information is received fromthe I/O control processor at the step 9010, and whether the brake SW isON or OFF is judged at the step 9020. And, if the brake SW is ON, thenthe ABS control processing is executed at the step 9030 and the processgoes back to the step 9010 of receiving the brake SW state informationfrom the I/O control processor. If the brake SW is OFF, then the ABSself-diagnosis and the OBD processing are executed at the steps 9040 and9060, respectively. And, the process goes back to the step 9010.

FIGS. 18(a) and (b) are flow charts showing another embodiment ofdetecting loads of other control processors by an I/O control processorin cooperatively controlling an automobile. In an I/O control programshown by FIG. 18(a), when a power turns on, initialization of a timer, aport, an A/D converter, a RAM, a transmission system, etc. is done atthe step 8001, an output signal of a brake SW is taken in at the step8011, and whether the brake SW is ON or OFF is judged at the step 8021.And, if the brake SW is ON, then the I/O control program sends theinformation of the brake-SW-ON at the step 8031 to the ABS controlprocessor. If the brake SW is OFF, then the I/O control program sendsthe information of the brake-SW-OFF at the step 8041 to an ABS controlprocessor and the process goes back to the step 8011. On the other hand,in an ABS control program shown by FIG. 18(b), when a power turns on,initialization of a timer, a port, an A/D converter, a RAM, atransmission system, etc. is done at the step 9001, the brake SW stateinformation is received from the I/O control processor at the step 9011,and whether the brake SW is ON or OFF is judged at the step 9021. And,if the brake SW is ON, then an ABS control processing is executed at thestep 9031 and the process goes back to the step 9011 of receiving thebrake SW state information from the I/O control processor. If the brakeSW is OFF, then an ABS self-diagnosis is executed at the step 9041. And,whether an OBD program was read out and written into the ABS controlprocessor from another processor is judged at the step 9051. If theprogram is already read out and written, then the OBD program isexecuted at the step 9061, and if it is not read out and written yet oranother program is already written, then the OBD program stored in theengine control processor is read out and written at the step 9071. Then,the read out and written OBD program is executed at the step 2061 andthe process goes back to the step 9011 of receiving the brake SW stateinformation from the I/O control processor.

FIG. 19 shows a block diagram of an embodiment in which integral typeprocessors are used for cooperatively controlling an automobile. Theintegral type processor system for cooperatively controlling anautomobile comprises an integrated ENG-AT-OBD control processor 60, anintegrated ABS-TCS control processor 61, an AirBS control processor 44,an I/O control processor 47, an integrated SUS-ASCD control processor62, an integrated NAVI-AV control processor 63 and an integratedLIGHT-PWST-PWWD-WIPER-A/C control processor 64 which are connected bysuch transmission means as LAN, BUS and so on. In such an integral typeprocessor, the load of each processor is measured by itself and thecontrol processing corresponding to the load information can beexecuted. Then, the control processing speed is increased by such anintegral type processor since the control data are commonly used by theintegrated control programs in the integral type processor.

By the present invention, it is possible to efficiently utilizeprocessors since each processor executes the necessary and minimum tasksbased on the control processing duty needed to be done in accordancewith the running states of an automobile and can execute another controlprogram stored in other processor.

What is claimed is:
 1. An automobile control method for controlling each part of an automobile using a plurality of control units, which are connected by transmission lines with each other, including computers and memories, comprising the step of:executing at least one of a plurality of control task programs stored in ones of said plurality of control units for controlling each part of the automobile, by at least one other of said plurality of control units having a lower processing load; wherein at least one of said plurality of control units having said lower processing load judges its having said lower processing load upon receiving information on running state changes of said automobile external to said plurality of control units, reads out at least one of said plurality of control task programs stored in other of said plurality of control units, and executes said at least one control task program.
 2. An automobile control system for controlling each part of an automobile, comprising:plural control units connected by transmission lines with each other, each control unit including a computer; a memory provided in at least one of said plural control units having a lower control processing load than other of said plural control units, said memory memorizing at least one of a plurality of control task programs stored in said other control units which is transferred to said memory via said transmission lines; means in each control unit for judging, upon receiving information on running state changes of said automobile external to said plurality of control units, when said at least one of said plural control units has said lower control processing load.
 3. An automobile control system according to claim 2, wherein said memory is an electrically rewritable memory, said electrically rewritable memory memorizing at least one of the plurality of control task programs stored in other of said plural control units having a high control processing load.
 4. An automobile control system according to claim 2, wherein said memory is a rewritable memory.
 5. An automobile control system according to claim 2, wherein said plural control units are of a same type; andwherein an address in said memory to which at least one of said plurality of control task programs is transferred being a same address in another memory of at least one of said other control units from which at least one of said plurality of control task programs is transferred.
 6. An automobile control system according to claim 2, wherein said plural control units are of different types; andwherein at least one of said control task programs is transferred in a source program form of C language, compiled by a C compiler and stored in said memory. 